Wear indicating attachment for drilling bits



Feb. 8, 1949. F. F. LEWIS 2,461,164

WEAR INDICATING ATTACHMENT FOR DRILLING BITS Filed March 19, 1947 'Farral Francis Lewis B; @MM

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Inventor Patented Feb. 8, 1949 UNITED STATES, PATENT OFFICE WEAR, INDICATING ATTACHMENT FOR DRILLING BITS Farral Francis Lewis, Houma, La.

Application March 19, 1947, Serial No. 735,628

2 Claims. (Cl. 255-61) The present inventionrelates to new and use- The invention is designed particularly for use I with drilling bits used in drilling wells and wherein it is important that the eiiiciency of the bit be maintained since drilling with a bit that is unduly worn causes delay in completing the drilling operation and causes the loss of time in attempting to drill with a dull or worn out drilling bit, as the cost of operation of an oil, gas or water well per day is quite expensive, depending upon the depth of the drilling operation.

Likewise the drilling bits are quite expensive and a partially worn bit may be easily repaired and rebuilt and it is therefore important that the bit should not become unduly worn beyond repair.

Accordingly, it is an object of the present invention to provide means carried by the bit to indicate when the blade has become dull or worn beyond its eflicient use.

More specifically this invention embodies the provision of a fluid container carried within the bit and including a tube leading from the container to a point adjacent the cutting edge of,

one of the blades of the bit, the lower end of the tube being closed by a weld and arranged for rupturing by a predetermined wear in the blade to allow the fluid to escape into the drill hole, said fluid being in the form of a liquid dye or a gas having a strong odor which is carried upwardly in the well with the return of the circulating mud and cutting from the bit to warn the driller of the worn condition of the bit.

A further object of the invention is to provide an indicating attachment for drilling bits of this character and in which the fluid may be replaced after the blades of the bit have been repaired.

Another object of the invention is to provide efiective means for discharging the fluid into the drill hole upon a predetermined wearing of the blades of the bit.

A still further object is to provide a device of this character of simple and practical construction, which is eflicient and reliable in operation, relatively inexpensive to manufacture and install in operative position and which is otherwise well adapted for the purposes for which it is intended.

Other objects and advantages reside in the details of construction and operation as more fully hereinafter described and claimed, reference bee ing had to the accompanying drawings forming part hereof, wherein like numerals refer to'like parts throughout, and in which :4

Figure 1 is a perspective view;

Figure 2 is a vertical sectional view, and

Figure 3 is a transverse sectional View taken substantially along the line 33 of Figure 1.

Referring now to the drawing in detail wherein for purposes of illustration I have disclosed a preferred embodiment of the invention. The numeral 5 designates a drilling bit of conventional construction and which includes the internally threaded socket 6 for threaded connection .to the drill rod or to the line of a circulating pump (not shown) in the usual manner and to the lower end of the socket are formed the blades 1. The bottom of the socket is also provided with the passages 8 to wash cuttings out of the hole.

A tubular cylinder or container 9 is open at each end and is externally threaded as at Ii! at its lower end for threading in a recess H at the inside of the bottom of the socket 6 and the upper end of the container is closed by a threaded plug I2 having a passage therethrough.

A tube 14 has its upper end positioned in the lower end of the container 9 in communication with the interior thereof near the bottom and extends downwardly through the bottom of the socket 6 and is recessed at its lower end along one inner side edge of one of the blades 1 as shown in Figure 1 of the drawing.

The lower end of the tube l4 terminates a predetermined distance above the lower cutting edge l5 of the blade I and is closed by a weld I6.

In the operation of the device plug I2 is removed from the containers which is then supplied with a quantity of indicating fluid I! which may be in the form of a liquid dye or a gas, that is, a chemical producing a gas or a fluid having a strong odor, a plunger I8 is placed in the container on top of the fluid and the plug l2 replaced thereabove. The drilling bit is now connected to the lower end of the drilling rod in the usual manner and the usual circulating or drilling fluid pumped down the drilling rod and out through the circulating passages 8 in the bit into the well bore to return to the top of the well. The plug I8 is subjected to the constant pressure of the circulating fiuid pumped downwardly through the drilling rod and bit as fluid under pressure enters the container through passage IS in the plug and exerts pressure on the plunger which in turn exerts pressure on the entrapped indicating fluid.

l3 extending vertically When the cutting edge ll: of the blade I becomes worn to the region of the lower end of the tube M the weld I6 closing the lower end of the tube will be ruptured or worn away whereupon the indicating fluid I! in the cylinder 9 will be discharged into the well and will be carried to the top of the well with the mud and cuttings of the bit and thus warn the driller by its color or odor of the exfient of wear in the blade and that the bit should be replaced to more efiiciently continue the drilling operation.

In view of the foregoing description taken in conjunction with the accompanying drawings it is believed that a clear understanding of the con-. struction, operation and advantages of the device will be quite apparent to those skilled in this art.

It is to be understood, however, that even though there is herein shown and described a preferred embodiment of the invention the same is susceptible to certain changes fully comprein the lower compartment of said receptacle and in said conduit, the upper compartment of said receptacle being in communication with said chamber whereby flushing fluid pressure is transmitted to said fluid indicating agent through the medium of said piston.

2. The device as defined in claim 1 wherein said body is provided with a bore communicating with said receptacle, said conduit comprising a tube positioned in said bore, said tube having an pper end portion projecting into the lower compartment of said receptacle, and a rupturable weld. on said body securing the lower end portion of; said tube in said bore.

FARRAL FRANCIS LEWIS.

REFERENCES CITED Ihe; following references are of record in the file of this patent: 

